<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="vue.js"></script>
</head>
<body>
<div id="app">
{{fullName}}
</div>
<script>
    var vm = new Vue({
         el: "#app",
        data: {
             firstName: "Dell",
            lastName: "Less"
        },
        computed: {
             fullName: {
                 get:  function () {
                     return this.firstName + " " + this.lastName;
                 },
                 set: function (value) {
                  console.log(value);
                 }
             }
        }


    })

</script>
</body>
</html>